Restore "new event" icon to monthly view for mobile devices. (v1.9.10)

[42daha]

Recently upgraded from 1.2.9 to 1.9.10, and I noticed that the "New event" icon is now missing from the monthly calendar view. While the double-click to create an event is nice on a desktop system, it doesn't work well on Android with Chrome because the double-click event is hooked to zoom-out, so the dblclick event handler for the table cell never gets called. It would be nice to have the "New Event" back for mobile devices. I enabled it on my own install by changing includes/functions.php, line 1101 to pass false for the last parameter ($disallowAddIcon) instead of true:

$ret_events = print_date_entries ( $dateYmd,
( empty ( $user ) ? $login : $user ), false, false );

Adding the ability to customize that via a system setting would be very nice. My family members have also found the "New event" icon to be very intuitive to use. None of them have figured out the double-click option so far. I found it because I happened to run across it in the documentation while looking for an option to bring the icon back.